The present invention is directed to the process for reducing the dust content of extrafine cobalt powder.
Extrafine pure cobalt metal powder is typically produced by the reduction of a cobalt hydroxide precipitate. Such pure cobalt powder has a tendency to include a cobalt dust portion. The dust is in the form of cobalt fines which tend to become airborne when the cobalt powder is transported such as pouring cobalt powder from one container to another.
U.S. Pat. No. 4,469,505 to Cheresnowsky et al relates to a process where a cobalt hydroxide precipitate is heat treated prior to reduction at a selected temperature for reducing the Fisher Sub Sieve Size of the finely produced metal powder. Screening the cobalt powder to obtain a powder of predetermined size is also disclosed. Screening through a 100 mesh size screen to is disclosed. Extrafine cobalt metal powder preferably has Fisher Sub Sieve Size less than 1.5.
Heretofore, efforts to control the particle size of finely produced extra fine pure cobalt metal powder were directed to enhancements of the chemical process for preparing the powder and techniques for sieving the finally produced powder.